# Total change in entropy, what am I missing?

• asdf188
However, it can be estimated that there will be a decrease in entropy due to the box coming to rest and a slight increase in entropy due to the heat transfer to the table and room. In summary, the total change in entropy of the universe is likely to be minimal.
asdf188
A 20.0 -kg box having an initial speed of 1.0 m/s slides along a rough table and comes to rest.
Estimate the total change in entropy of the universe. Assume all objects are at room temperature (293 K).

I don't understand how to answer this problem. It feels like I wasn't given enough information to solve for Delta S.

asdf188 said:
A 20.0 -kg box having an initial speed of 1.0 m/s slides along a rough table and comes to rest.
Estimate the total change in entropy of the universe. Assume all objects are at room temperature (293 K).

I don't understand how to answer this problem. It feels like I wasn't given enough information to solve for Delta S.
Assume that the kinetic energy of the box is dissipated as heat and that this heat is absorbed by the table and room at a constant temperature (ie the temperature of the table and room does not change).

Hint: Since the box does not lose any heat, there is 0 change in the entropy of the box. However, the table gains heat.

AM

To calculate the total change in entropy, we need to consider the entropy changes of both the box and the table. The box has an initial kinetic energy due to its motion, but as it slides along the rough table, it will experience friction and lose some of that energy. This energy is converted into heat, which increases the entropy of the box and the table. Additionally, the box and the table will also experience a decrease in temperature as they come to rest, which will also contribute to an increase in entropy.

To calculate the exact change in entropy, we would need to know the specific heat capacities and masses of both the box and the table, as well as the coefficient of friction between them. We would also need to consider the surroundings and any energy exchanges with them.

In general, the total change in entropy of the universe can be calculated by considering all energy transfers and transformations within the system, as well as any energy exchanges with the surroundings. Without this information, it is not possible to accurately estimate the total change in entropy in this scenario.

## 1. What is total change in entropy?

The total change in entropy is a measure of the overall disorder or randomness in a system. It takes into account both the change in entropy of the system itself and the surroundings.

## 2. How is total change in entropy calculated?

The total change in entropy is calculated by adding the change in entropy of the system to the change in entropy of the surroundings. The change in entropy of the system is determined by the change in temperature and the amount of energy released or absorbed during a process. The change in entropy of the surroundings is determined by the change in temperature and the amount of energy transferred to or from the system.

## 3. What factors affect the total change in entropy?

The total change in entropy is affected by changes in temperature, energy transfer, and the number of particles present in a system. Generally, processes that lead to an increase in temperature and energy transfer result in an increase in total entropy, while processes that lead to a decrease in temperature and energy transfer result in a decrease in total entropy.

## 4. How does total change in entropy relate to the second law of thermodynamics?

The second law of thermodynamics states that the total entropy of a closed system can never decrease over time. This means that the total change in entropy must always be greater than or equal to zero. In other words, the total change in entropy can only increase or remain constant, never decrease.

## 5. What is the significance of total change in entropy in scientific systems?

The concept of total change in entropy is important in many scientific systems, as it helps to explain and predict the direction and outcomes of processes. It is especially useful in thermodynamics, where it provides a measure of the efficiency of energy conversion and the direction of heat flow. It is also relevant in fields such as chemistry, biology, and environmental science, where it can help to understand the behavior of complex systems.

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